More eprops for the viola. Kim Kashkashian in particular is fantastic, almost everything she does she pulls off great. I'm a particular fan of the Elegies album, especially the Vaughan Williams and the Kodaly.

Brahms: Piano Trios (Suk/Katchen/Starker or the Isaac Stern trio), Violin Sonatas (Suk/Katchen), basically almost all Brahms chamber music (there is an excellent box set by the Amadeus Quartet of Brahms chamber music)

I love the 11 cd collection by Maxim Vengerov. He is a fantastic violinist and this collection includes many famous concertos for violin and orchestra as well as some sonatas and other virtuosic type pieces.... and it looks like its going for just $27 on Alibris!